Method and device for maintaining a constant temperature control of a sinker bar assembly in a straight bar knitting machine



y 1961 A. J. COBERT 2,983,127

METHOD AND DEVICE FOR MAINTAINING A CONSTANT TEMPERATURE CONTROL OF A SINKER BAR ASSEMBLY IN A STRAIGHT BAR KNITTING MACHINE Filed March 27, 1958 United States Patent Orifice 2,983,127 Patented May 9, 196.1

METHOD AND DEVICE FOR MAINTAINING A CONSTANT TEMPERATURE CONTROL OF A SINKER BAR ASSEMBLY IN A STRAIGHT BAR KNITTING MACHINE Arthur J. Cobert, Chattanooga, Tenn, assignor to Societe Beige DOptique et DInstruments de Precision, Societe Anonyme, Ghent, Belgium, a corporation Filed Mar. 27, 1958, Ser. No. 724,404

Claims priority, application Belgium Dec. 12, 1957 7 Claims. (CI. 66-82) The present invention relates to improvements in straight bar knitting machines, and more particularly to an improved method and device for maintaining a constant temperature control of a sinker bar assembly and the continued accurate register of the sinkers with the several cooperating instrumentalities along the length of a multiple section full-fashioned knitting machine.

Because even the slightest temperature change in the metal parts will cause an appreciable contraction or expansion of the metal partsalong the length of the machine with a corresponding loss of register of the knitting elements and breakage of parts, a constant temperature control within close limits, preferably within a degree, is always maintained in the knitting rooms in which the machines are housed.

A further problem is posed by the tendency of certain machine assemblies, in which there is frictional movement of the parts, notably the friction sliding movement of the sinkers of the sinker bar. assembly, to heat up over an extended period of operation with the result that the sinker bar becomes elongated with relation to the cooperating needles, narrowing machine and other assemblies with a resulting loss of register and damage to the machine.

Elforts have been made through a pre-heating and adjustment of the sinker bar in the heated condition with relation to cooperating knitting assemblies to overcome this tendency. The individual needle bar units may be mounted in the machine to move axially with the associated portions of the sinker bar to further reduce the chance of interference between the sinker and needle assemblies.

Corrections made in this manner, however, do not provide for the continued accurate register of certain other auxiliary units along the length of the machine including, for example, the narrowing machine needles. It has been found also that heating units, however, placed, tend to heat other adjacent knitting assemblies including the needles in varying degree with resulting uncertainties in the operation of the machine.

The present invention contemplates the provision of an improved device for maintaining several knitting assemblies of the machine and more particularly the sinker bar assembly at a constant unvarying temperature which will be automatically maintained during continued operation of the machine for extended periods of time.

It is a principal object of the invention to provide a novel means to dissipate any heat generated by the frictional back andv forth movement of the sinkers in the sinker beds in such a manner as to insure the continued satisfactory operation of the machine without loss of register of the knitting instrumentalities.

' More specifically, it is an object of the invention to provide 'a' cooling system-which is automatically controlled to dissipate any heat generated in the sinker bar assembly during continued operation of the machine, and thereby to maintain this assembly at any desired temperature which may, for example, be the normally maintained room temperature without in any way affecting or disturbing the adjustment of the other operating instrumentalities of the machine.

With the above and other objects in view as may hereinafter appear, the process according to the invention consists first of all in designing these machine parts in such way that. due account is taken of the rates of expansion at the mean temperature of the room in which aforesaid machines will operate, so that the parts in question will operate under normal conditions at this mean temperature, and further consists in maintaining such parts which are subjected to friction, at aforesaid mean room temperature by means of a cooling device.

So for instance, in the case of a knitting machine, the sinker bed will be permanently kept at a temperature which is very close to the room temperature by means of a cooling device based on the use of a liquid or other coolant.

According to the invention, if a cool liquid is pumped or forced through tubing which in turn is fixed in positive contact with the sinker bed, the generated heat can be dissipated into the liquid, thus keeping the sinker bed in a hi h degree of stability and therefore ensuring that the needles, sinkers and other related elements will remain in very good register with one another.

A second advantage of this system is the fact that a a cooling device of this kind will not draw-0E heat from parts of the machine which are not directly connected to it. So, for instance, the narrowing frame will not be affected in any way by the cooling system. If a fairly sensitive thermostat is used at the sinker bed, the temperature of the latter can be kept within close enough limits for preventing an appreciable elongation from taking place, thus keeping the sinkers in a constantly centered position with respect to the needles, narrowing points and other related elements,

A third advantage ensues from the fact that, as the sinker heads, jacks and jack heads are kept properly centered, they are no longer subjected to friction and therefore undergo much less wear.

The replacement of a heating system by a cooling system carries a further advantage. It is much easier to adjust a knitting machine at room temperature than to do so at an elevated temperature, since the related parts will retain their dimensions at their relative positions at all times. This will result in a great saving on account of less needle breakage and sinker damage, as well as of .a higher percentage of first quality goods being issued from the machine.

The device for applying the process according to the invention is illustrated in the following drawings, in which:

Figure 1 is a very diagrammatic representation of the cooling device, subject matter of the invention;

Figure 2 is a side view of a sinker head mounted on a sinker bed and equipped according to the invention;

Figure 3 is a side view of a sinker bed equipped according to the invention;

Figure 4 is a schematic representation of an alternative design for the cooling device, object of the invention.

In Figure 1, 1 refers to the part or parts of the machine which .have been designed and constructed with due regard to the rates of expansion at the mean room temperature of the workshop and which must be permanently maintained at this temperature or very nearly so. One or more tubes 2 made of material of high thermal conductivity, such as copper, are mounted in direct contact with those parts of the machine the temperature of which is to be stabilized.

Thoes tubes 2 are part of a circuit consisting mainly of an inlet tube 3, a pump 4, another tube 5, a container 'machine 1 the temperature of which must be stabilized.

Considering for instance, the application of this cooling 7 would "be possible to feed into container as wate temperature is 3 which need might arise in some exceptional circumstances 3 with constant level device 6 and an outflow 7. Container 6 is fitted with an overflow 8; tube 5 issues from the bottom of container 6, and tube 7 is connected to the aforesaid container 6 at a higher level than aforesaid overflow 8. A cooling liquid, such as cold water for instance, is fed into the upper parrot aform'aid container 6 by means of a tube 9. The opening and closing of the inlet tube 9 is controlled by a magnetic valve 1% This valve is energized by an electric circuit controlled by a thermostat 11 located in and on the bottom of container 6. The circulation pump 4 can be driven by an electric motor 12 through a belt 13. The electric circuit of this motor 12 is controlled by a thermostat 14 in contact with or' influenced by the temperature of the part or parts ofv system'to the temperature stabilizationof a sinker head as shown in Figure 2, or of a sinker bed as represented in Figure 3, aforesaid tubes 2 which are :connected in the cooling jliquid circuit and are made of a material with high thermal conductivity, are fastened onto the sinker head 15 by appropriate clamps 16 as shown in Figure 2, and onto the sinker bed 17 by adequate clamps 18 as shown in Figure 3.

Container -6'may be located on or near the machine. Thermostat 14 is mounted in the lower part of sinker bed 17 as shown in Figures 2 and 3.

A certain number of tubes 2 may be connected in the cooling circuit, depending on the number or on the length of the parts of machine 1, the temperature of which is to be kept constant. Tubes 3, 5, 7 may be either rigid tubes orhoses. The level of cooling liquid or of cooling Water in container 6, is maintained constant by the overflow 8. Pump 4 is connected to the outlet of container 6 and to 't heinlet '3 of the cooling'tubes 2. The coolant or cooling water which has passed through aforesaid tubes 2 is returned to the container 6 by tube 7. The cooling water mentioned by way of example contained in aforesaid cooling circuit, automatically reaches the actual temperature .of the parts of machine 1 which must be protected from expansion. If the temperature of these parts has a tendency to rise, the excess heat to which this temperature is due is transferred to the tubes 2 and hence carried away by the water which starts circulating in the circuit on account of the fact that when thermostat 14 operates, it

closesthe circuit of motor 12 which drives the pump 4.

Fo'r making sure that the cooling water will at all times be able to answer its purpose of stabilizing the temperature of the parts 1, provision must' be made for lowering the temperature of -the water itself, if need be. To this eitect temperature is permanently controled in container 6 by thermostat 11.i if the temperature in question should riseiabove a predetermined limit, aforesaid thermostat 11.

closes the circuit of magnetic valve 19 Whichthereby opens tube 9 to the inflow of fresh water issuing from an appropriate source (not represented); The level in container 6 remains constant on account of overflow 8, but the temperature of the water will drop until it has reached a temperature which is very close to the actual temperature of the machine; when this happens, thermostat 11 will operate again, opening the circuit of magnetic valve which thereby will close and stop the inflowof fresh If no dangerous temperature rise occurs in the parts 1 under control, the cooling fluid stops flowing.

In certain circumstances, it is also possible to use a simplified design, such as the one which is illustrated diagrammatically in Figure 4. a

As in the preceding example, the parts 1 the temperature of which must be controlled, arc'in Contact with the tubular elements 2 made of a material of high thermal conductivity. These tubular elements 2 are a part of a circuit comprising a container, 6, a tube 19 connecting the bottom of aforesaid container 6 to the inlet of aforesaid tubular elements 2, and a tube 20 connecting the highest level which is likely to be attained by the cooling fluid in container 6, to the outlet of aforesaid tubular elements 2. At this very same level, an overflow S is fitted to the reservoir 6 and, at a higher level, an inflow tube 9 for an additional cooling fluid, whereby inflow tube 9 is controlled by the magnetic valve 1% The latter is energized by a circuit containing thermostat 14.

As can be seen, this simplified design does not contain any pump, electric motor or'thermostat controlling the temperature in container 6. This system operates on the well known therm'o-siphon principle, and the temperature of the cooling fluid is maintained within the predetermined limits by the combined action of thermostat 14 and of the additional amount of coolant, such as fresh water 'for instance, controlled by the magnetic valve 10.

Other means could, of course, be devised for fulfilling the conditions of temperature stabilization according to the present invention.

The invention having been described what is claimed is:-

1. In a straight bar knitting machine having a machine frame, a sinker bar assembly including a sinker bar estending along the length of the machine, sinker beds and sin-kers slidably mounted therein, and cooperating knitting assemblies including a series of needles movable as a unit,-the method o f-mainta'ininga constant unvarying temperature of the sinker bar assembly consistent with the established mean room temperature and adjustments for registering of the several cooperating knitting assemblies of the machine during continued machine operation which comprises the steps of applying athermal cooling medium in contact with the sinker assembly for dissipating heat generated in the sinker bar assembly by the sliding movement of the sinkers, adjusting the heat HlSSlPHl,

activity of said thermal cooting medium, and thermostatically controlling the adjustmentof said heat dissipating activityof that ermal cooling medium in response to temperature changes of said sinker assembly to main tain-t-he temperature of said sinker bar assembly at a constant value consistent with said established temperature and --adju stments 'for registering of the several cooperating knitting assemblies ofthe' machine during conwater intor eservoir 6 via tube 9. In a similar wa it 1' whose higher than that of the circulating water,

whenthe'temperature of the parts'i would drop under the lowerpredetermined'limit of temperature at which the quarts should operate, i.e., the temperature for which these parts have been designedv bytaking into account their coefficients of expansion. 7 I

If-ZlS. obviousthatthe thermostats i1 and 14. must be minimum and maximum thermostats of which the differperature of the sinker bar assembly consistent with the established mean room temperature and adjustments. for registering the several cooperating knitting assemblies of thelmachine during machine operation which comprises the steps of circulating a cooling fiuidinto thermally effective contact with the sinkeria'ssembly for "dissipating heat generated in the sinker bar assembly by the sliding movement of the. sinkers, adiustingthe circulation of said cooling fluid to. dajust :the rate of heat dissipating activity of the cooling .fiuid, 'a'nd tthermostatically.controllingthe adjustment of saidtrateof circulation ,dfithe cooling fluid.

j in response to temperature changes of 'saidl'sinker ,bar

I assembly tomaiutain the temperature of. said sinker ,bar assembly ata constantvalue'tconsistmt with .saiclsestab-i lrshed temperature .and-..adjustmentspforregistering of the several cooperating knitting assemblies of the machine during continued machine operation.

3. In a straight bar knitting machine having a machine frame, a sinker bar asesmbly including a sinker bar extending along the length of the machine, sinker beds and sinkers slidably mounted therein, and cooperating knitting assemblies including a series of needles movable as a unit, said assemblies being adjusted with relation to one another for operation at an established mean room temperature, the combination of a cooling system for dissipating heat generated in the sinker ba. assembly for sliding movement of the sinkers, and thereby for maintaining constant the temperature of said sinker bar assembly at a value consistent with the established temperature and adjustments for registering of the several cooperating knitting assemblies of the machine during continued machine operation, which comprises at least one thermal cooling element disposed with relation to said sinker bar and sinker beds to dissipate heat generated by continued sliding movement of the sinkers, means for adjusting the heat dissipating activity of said thermal cooling unit, and thermostatic means responsive to temperature changes of said sinker assembly at a constant value the temperature of said sinker bar assembly.

4. A cooling system for dissipating heat generated in the sinker bar assembly of a straight bar knitting machine according to claim 3 which comprises at least one tubular cooling element which is mounted with relation to the sinker bar and sinker beds to dissipate heat generated by sliding movement of the sinkers, and means for circulating a cooling fluid through said tubular cooling element, including a thermostat responsive to temperature changes of said sinker assembly to control the circulation of said cooling fluid to maintain said cooling element and sinker bar assembly at a temperature consistent with the established temperature and adjustments for registering the several cooperating knitting assemblies of the machine during continued machine operation.

5. In a straight bar knitting machine having a machine frame, a sinker bar assembly including a sinker bar extending along the length of the machine, sinker beds and sinkers slidably mounted therein, and cooperating knitting assemblies including a series of needles movable as a unit, said assemblies being adjusted with relation to one another for operation at an established mean room temperature, the combination of a cooling system for dissipating heat generated in the sinker bar assembly by the sliding movement of the sinkers and thereby for main taining constant the temperature of said sinker bar assembly at a value consistent with the established temperature and adjustments for registering of the several cooperating knitting assemblies of the machine during continued machine operation, which comprises a cooling fluid, at least one tubular cooling element disposed with relation to said sinker bar and sinker beds to dissipate heat generated in said sinker bar assembly by continued sliding movement of the sinkers, a coolant reservoir, conduits through which said cooling fluid is circulated from the reservoir to the tubular cooling element and is returned to the reservoir, and thermostatic means responsive to changes of temperature of the sinker bar assembly to vary the circulatory flow of said cooling fluid.

6. In a straight bar knitting machine having a machine frame, a sinker bar assembly including a sinker bar extending along the length of the machine, sinker beds and sinkers slidably mounted therein, and cooperating knitting assemblies including a series of needles movable as a unit, said assemblies being adjusted with relation to one another for operation at an established mean room temperature, the combination of a cooling system for dissipating heat generated in the sinker bar assembly by the sliding movement of the sinkers and thereby for maintaining constant the temperature of said sinker bar assembly, which comprises a cooling fluid, at least one tubular cooling element disposed with relation to said sinker bar and sinker beds to dissipate heat generated by continued sliding movement of the sinkers, a coolant reservoir, conduits through which said cooling fluid is circulated from the reservoir to the tubular cooling element and is returned to the reservoir, a cooling fluid supply and spill conduits to said reservoir, means including a thermostat for controlling the supply or" cooling fluid to said reservoir to maintain said cooling fluid in the reservoir at a cooling temperature, a pump for circulating the cooling fluid between the reservoir and cooling unit, and a thermostat responsive to temperature changes of said sinker assembly to control the operation of the pump to maintain at a substantially constant value the temperature of said sinker bar assembly.

7. In a straight bar knitting machine having a machine frame, a sinker bar assembly including a sinker bar extending along the length of the machine, sinker beds and sinkers slidably mounted therein, and cooperating knitting assemblies including a series of needles movable as a unit, said assemblies being adjusted with relation to one another for operation at an established mean room temperature, the combination of a cooling system for dissipating heat generated in the sinker bar assembly by the sliding movement of the sinkers and thereby for maintaining constant the temperature of said sinker bar assembly, which comprises a cooling fluid, at least one tubular cooling element disposed with relation to said sinker bar and sinker beds to dissipate heat generated by continued sliding movement of the sinkers, a coolant reservoir, a conduit through which said cooling fluid passes to the reservoir and a return conduit from the cooling element to the reservoir by thermal syphonic action, a spill conduit from the reservoir at the same level with the return conduit, a supply conduit to the reservoir, valve means actuable to vary the flow of cooling fluid to the reservoir from the supply, and a thermostat responsive to temperature changes of said sinker assembly to actuate said valve means to maintain at a substantially constant value the temperature of said sinker bar assembly.

References Cited in the file of this patent UNITED STATES PATENTS 1,971,316 Meyer Aug. 21, 1934 2,354,188 Aschenbrenner July 25, 1944 2,709,350 Meyer May 31, 1955 

